Guide member for a lawnmower

ABSTRACT

A lawnmower including a cut grass storage container for storing cut grass. The lawnmower also includes a cutting blade, a downwardly-opening housing, and a cut grass conveyor passage. The cut grass storage container is provided to the cut grass conveyor passage. Grass that has been cut is delivered to the cut grass conveyor passage while revolving about a shaft inside the housing. A guide member is provided inside the housing. The guide member guides the revolving grass to the cut grass conveyor passage while guiding the grass to the outer periphery of the housing.

FIELD OF THE INVENTION

The present invention relates to a rotary lawnmower that can be used ina bagging mode.

BACKGROUND OF THE INVENTION

A rotary lawnmower cuts grass by rotating a cutting blade along thegrass, the cutting blade being housed in a housing which is open at thebottom. Such lawnmowers include lawnmowers designed to be used in abagging mode. A lawnmower used in bagging mode stores the grass cut bythe cutting blade (i.e., the cut grass) in a bag or another cut grassstorage container, and since all of the cut grass can be removed, theresults of cutting grass with this lawnmower are superior, and suchlawnmowers are widely used in golf courses and the like. Known examplesof lawnmowers that can be used in a bagging mode are disclosed in U.S.Pat. No. 4,951,449 and Japanese Patent No. 3771529.

The housing of the lawnmower disclosed in U.S. Pat. No. 4,951,449 is abagging mode housing in which a grass discharge chute extends rearwardand upward from a top wall. By attaching and removing a chute plug toand from the grass discharge chute, the bagging mode housing can beswitched between bagging mode and mulching mode. In mulching mode, thecut grass is cut even finer within the housing, discharged out below thehousing, and returned to the lawn.

The cutting blade cuts grass by rotating around a shaft substantiallyperpendicular to the lawn, and creates a revolving flow around the shaftwithin the housing. When the lawnmower is used in bagging mode, the cutgrass is delivered to the grass discharge chute while being made torevolve around the shaft within the housing by the revolving flow. Thespeed of the revolving flow in the vicinity of the shaft is much lowerthan the speed of the revolving flow in the outer periphery of thehousing. Therefore, the cut grass may stop around the shaft (a problemknown as grass buildup can occur). The occurrence of grass buildup mustbe prevented in order for all of the cut grass in the bag from thehousing to be efficiently stored in the bag via the grass dischargechute.

The lawnmower disclosed in Japanese Patent No. 3771529 can be manuallyswitched between a bagging mode for fully opening a shutter and storingcut grass in a cut grass storage container, a mulching mode for fullyclosing the shutter and discharging the cut grass out below the housing,and an intermediate mode between the housing mode and the mulching mode,wherein the shutter is set to the desired open position. The lawnmowerdisclosed in Japanese Patent No. 3771529 has the same problems as thelawnmower disclosed in U.S. Pat. No. 4,951,449.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide alawnmower in which the storage performance of storing cut grass in a cutgrass storage container can be improved.

According to the present invention, there is provided a lawnmower whichcomprises: a cutting blade capable of rotating about a shaft extendingsubstantially perpendicular to a lawn; a downwardly-opening housing forhousing the cutting blade; and a cut grass conveyor passage extendingrearwardly from the housing and designed to allow attachment of a cutgrass storage container thereto, the grass cut by the cutting bladebeing delivered to the cut grass conveyor passage while revolving abouta shaft within the housing, wherein the housing has a guide memberprovided therein for guiding the grass revolving about the shaft towardan outer periphery of the housing while also guiding the grass to thecut grass conveyor passage.

In the present invention, the cutting blade cuts grass and creates arevolving flow around the shaft within the housing. The grass that hasbeen cut (in other words, the cut grass) is made to revolve around theshaft within the housing and is delivered to the cut grass conveyorpassage by the revolving flow. The speed of the revolving flow in theouter periphery of the housing is higher than the speed of the revolvingflow in the vicinity of the shaft. The guide member provided in theinterior of the housing guides the cut grass revolving at a low speedaround the shaft to the outer periphery of the housing where therevolving flow is faster, while also guiding the cut grass to the cutgrass conveyor passage. Therefore, since the revolving cut grass flowssmoothly, the cut grass can be prevented from stopping around the shaft(a problem known as grass buildup). Since the problem of grass buildupcan be resolved, the lawnmower can be cleaned and inspected lessfrequently. Moreover, substantially all of the cut grass revolves at afast speed. Substantially all of the cut grass can be quickly deliveredfrom the housing to the cut grass conveyor passage and efficientlystored in the cut grass storage container. As a result, the storageperformance with which the cut grass is stored in the cut grass storagecontainer can be improved. Moreover, it is sufficient for the guidemember to have a simple configuration of merely being provided insidethe housing.

Preferably, the housing comprise a substantially horizontal top wall, anexternal cylinder and an internal cylinder disposed around the shaft andextending downward from the top wall, and an annular space defined bythe top wall, the external cylinder and the internal cylinder. Theannular space may be formed so that cut grass is directed to the cutgrass conveyor passage while revolving. The guide member may be disposedin the space at a corner between the top wall and the internal cylinder,or in proximity to the corner.

In the housing, the annular space enclosed by the top wall, the externalcylinder, and the internal cylinder is a passage through which the cutgrass revolves, and within this passage, the guide member is disposed inthe corner between the top wall and the internal cylinder or inproximity to the corner. The passage through which the cut grassrevolves is formed into a downward-facing U shape. The speed of the flowwhich revolves through the annular passage is lowest in proximity to theinternal cylinder. The guide member is disposed in the corner betweenthe top wall and the internal cylinder or in proximity to the corner,where the flow speed is low. The guide member guides the grass revolvingat a low speed to the external cylinder where the flow speed is high.Therefore, the revolving cut grass can be efficiently prevented fromstopping around the shaft.

Preferably, the guide member is formed into a triangular shape whichtapers in a direction opposite the direction in which the grassrevolves. Consequently, the revolving flow is efficiently dispersed inthe radial direction of the housing by the triangular guide member.Therefore, the cut grass revolving at a low speed can be efficientlyguided in the radial direction of the housing.

Desirably, the housing has a shutter mechanism and a kicker. The shuttermechanism may be rendered capable of being switched between a baggingmode in which the cut grass conveyor passage is opened so that the grassis delivered from the housing to the cut grass storage container, and amulching mode in which the cut grass conveyor passage is closed so thatthe grass is discharged out below the housing. The kicker may be amember for regulating the revolving flow of the grass within the housingand guiding the grass to a bottom of the housing during the mulchingmode, and is disposed inside the housing in a section close to theexternal periphery of the housing or in proximity to the section.

Specifically, the shutter mechanism opens and closes the cut grassconveyor passage. When the cut grass conveyor passage is closed by theshutter mechanism, the lawnmower switches from the bagging mode to themulching mode. In the mulching mode, the cut grass is discharged outbelow the housing and returned to the lawn. The kicker is a member forregulating the revolving flow of the cut grass within the housing andguiding the cut grass to the bottom of the housing during the mulchingmode, and is disposed inside the housing in the outer peripheral portionof the housing or in proximity thereto. The revolving flow and the flowof cut grass revolving within the housing are guided to the bottom ofthe housing by the kicker.

As described above, the kicker is positioned in the outer peripheralportion of the housing or in proximity thereto, and the kicker regulatesthe flow of cut grass revolving within the housing while guiding theflow downward. The guide member guides the cut grass revolving at a lowspeed around the shaft within the housing to the outer peripheralportion of the housing. Thus, since both the guide member and the kickerare disposed inside the housing, during the mulching mode, the flow ofcut grass revolving within the housing can be dispersed so as to beuniform. Moreover, the problem of grass buildup can be prevented by theguide member. Therefore, when the lawnmower is used in the mulchingmode, the cut grass can be efficiently discharged out below the housing.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the present invention will be described indetail below, by way of example only, with reference to the accompanyingdrawings, in which:

FIG. 1 is a side elevational view of a lawnmower according to thepresent invention;

FIG. 2 is a top plan view of the lawnmower of FIG. 1;

FIG. 3 is a cross-sectional view showing the lawnmower of FIG. 1;

FIG. 4 is a bottom view showing the lawnmower of FIG. 1, with a cuttingblade and a shutter mechanism removed;

FIG. 5 is a bottom view showing the lawnmower of FIG. 1;

FIG. 6 is an enlarged cross-sectional view taken along line 6-6 of FIG.5;

FIG. 7 is a perspective view showing a housing and a guide member ofFIG. 5;

FIG. 8 is a cross-sectional view taken along line 8-8 of FIG. 5;

FIG. 9 is a cross-sectional view taken along line 9-9 of FIG. 5;

FIG. 10 is a perspective view showing a shutter body and a kicker ofFIG. 5;

FIG. 11 is a schematic view showing the shutter body of FIG. 9 placed ina half-open position;

FIG. 12 is a schematic view showing the shutter body of FIG. 9 placed ina fully open position;

FIG. 13 is a view showing the shutter body of FIG. 5 placed in a fullyclosed position;

FIG. 14 is a view showing the shutter body of FIG. 5 placed in ahalf-open position; and

FIG. 15 is a view showing the shutter body of FIG. 5 placed in a fullyopen position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A lawnmower 10 according to the present embodiment is a walk-behindself-propelled work machine for cutting grass, comprising a housing 11,left and right front wheels 12, 12 provided to the front part of thehousing 11, left and right rear wheels 13, 13 provided to the rear partof the housing 11, a grass-cutting blade 14 housed in the centralinterior of the housing 11, an engine (drive source) 15 provided on thetop part of the housing 11, and an operating handle 16 extendingrearward from the housing 11, as shown in FIGS. 1 and 2.

In this lawnmower 10 in the plan view shown in FIG. 2, the cutting blade14 is rotated in a clockwise direction (in the direction of the arrowRa) by the engine 15, whereby grass is cut; an air flow (revolving flow)as indicated by the arrow Rb is created inside the housing 11, and thegrass cut by the cutting blade 14 can be blown by this revolving flowinto a cut grass storage container 22, where the grass is stored. Thegrass cut by the cutting blade 14 is hereinbelow referred to as “cutgrass.”

The housing 11 also fulfills the role of a chassis, and the engine 15 isintegrally assembled on the top surface of the housing by beingsuperposed and bolted thereon, as shown in FIGS. 1 and 3. The engine 15has an output shaft 15 a extending downward from the lower end towardthe lawn (ground surface) Gr (FIG. 1) into the housing 11. This outputshaft 15 a is a drive shaft substantially perpendicular to the lawn Gr.

Inside the housing 11 the cutting blade 14 is attached to the outputshaft 15 a via a clutch 18, and a drive pulley 19 for transmitting powerto a continuously variable transmission (not shown) for movement is alsoattached to the output shaft 15 a. The cutting blade 14 is driven by theengine 15 via the clutch 18, whereby the cutting blade 14 is capable ofrotating about an axis SC of the output shaft 15 a as a center (capableof rotating around the output shaft 15 a) within the housing 11. Therear wheels 13, 13 (FIG. 1) are driven by the engine 15 via thecontinuously variable transmission, whereby the lawnmower 10 can bepropelled forward and the grass-cutting work can proceed.

The details of the housing 11 are described hereinbelow. The housing 11is a so-called downward-opening housing in which only the bottom endsurface (the surface facing the lawn Gr) is fully open, as shown inFIGS. 1, 4, and 5. Moreover, the housing 11 is a spiral casing (spiralcase, scroll case) having a scroll part 11 d (FIG. 4).

In bagging mode, the scroll part 11 d causes the grass cut by thecutting blade 14 (FIG. 5) to move in a revolving manner in the directionof the arrow Rc (revolving direction Rc) through the housing 11, anddirects the grass into a cut grass conveyor passage 21 as indicated bythe arrow Rb, as shown in FIG. 4.

The housing 11 is composed of a top wall 11 a, an external cylinder(tubular part) 11 b, an internal cylinder (tubular part) 11 c, thescroll part 11 d, and the cut grass conveyor passage 21, as shown inFIGS. 3 through 6. The top wall 11 a closes off the top end of thehousing 11, and the top wall 11 a is a substantially horizontal wallhaving a substantially annular shape in a plan view. The externalcylinder 11 b is a cylindrical member centered around the output shaft15 a and extending downward from the external edge of the top wall 11 a.The internal cylinder 11 c is a cylindrical member centered around theoutput shaft 15 a and extending downward from the internal edge of thetop wall 11 a, and is formed so as to be smaller in diameter than theexternal cylinder 11 b.

The cut grass conveyor passage 21 is a member extending in a directiontangential to the external cylinder 11 b, rearward (more specifically,rearward and upward) from the external cylinder 11 b. This cut grassconveyor passage 21 has a passage opening 23 facing into the housing 11at the front end, and a grass bag or other cut grass storage container22 (FIG. 1) is attached at the rear end. The cut grass storage container22 can be detached from the cut grass conveyor passage 21. The cut grassis blown to the cut grass conveyor passage 21 while revolving around theoutput shaft 15 a inside the housing 11.

As is made clear from the above description, the direction in which thecut grass conveyor passage 21 extends from the external cylinder 11 bcoincides with the rotational direction Ra of the cutting blade 14. Inother words, the cut grass conveyor passage 21 extends in a directiontangential to the rotational arc of the cutting blade 14. The passageopening 23 opens into the rotational direction Ra of the cutting blade14.

The scroll part 11 d is a space having a substantially annular shape ina plan view, the space being enclosed by the top wall 11 a, the externalcylinder 11 b, and the internal cylinder 11 c, as shown in FIG. 6.Within this space 11 d, a corner 11 e (outside corner 11 e) between thetop wall 11 a and the external cylinder 11 b and a corner 11 f (insidecorner 11 f) between the top wall 11 a and the internal cylinder 11 care formed into comparatively wide arcs. The scroll part 11 d is formedinto a downward-facing U shape when viewed from the side and is apassage through which cut grass revolves, and is also configured so thatthe cut grass is directed to the cut grass conveyor passage 21 (seeFIGS. 3 and 4) while revolving. In other words, the scroll part 11 dleads to the passage opening 23 (FIG. 4) of the cut grass conveyorpassage 21.

The housing 11 has a first guide member 25 in the interior, as shown inFIGS. 5 through 7. The guide member 25 guides cut grass revolving in therevolving direction Rc around the output shaft 15 a into the cut grassconveyor passage 21 while guiding the cut grass toward the externalperiphery of the housing 11 as indicated by the arrow W1 (i.e., towardthe internal peripheral surface of the external cylinder 11 b), as shownin FIG. 7.

More specifically, the guide member 25 is disposed in the scroll part 11d (the passage 11 d), in the inside corner 11 f or in proximity thereto.For example, the entire guide member 25 is firmly bonded to the insidesurface of the scroll part 11 d, and is attached to the top wall 11 a bya screw 26, or by welding, caulking, or other various attachmentconfigurations. This type of guide member 25 is formed so as to have asubstantially triangular shape in both a plan view (underside view aswell) and a side view, so as to taper in the direction opposing therevolving direction Rc in which the cut grass revolves, i.e., in theopposite direction of the revolving direction Rc.

When the housing 11 is viewed from the bottom side, the guide member 25has the following configuration.

A tapering distal end 25 a in the guide member 25 is positioned in theinside corner 11 f. One side 25 b in the triangular guide member 25 isconnected along the external side of the internal cylinder 11 c. Thisside 25 b is inclined so that the part in the tapering distal end 25 ais nearest to the top wall 11 a, and as the side moves in the revolvingdirection Rc it becomes progressively farther away from the top wall 11a. The part in the side 25 b at the rear end 25 c is farthest from thetop wall 11 a.

When the housing 11 is viewed from the bottom side, the three apexes ofthe triangular guide member 25 are defined as follows. The taperingdistal end 25 a is referred to as the “first apex 25 a.” The rear end 25c is referred to as the “second apex 25 c.” The remaining end 25 d isreferred to as the “third apex 25 d.” The third apex 25 d is in contactwith the top wall 11 a.

The revolving current flow is efficiently dispersed in the radialdirection of the housing 11 by the substantially triangular guide member25. Therefore, in the vicinity of the inside corner 11 f, cut grassrevolving at a low speed can be efficiently guided in the radialdirection of the housing 11 (radially outward with respect to theinternal cylinder 11 c).

Furthermore, in the housing 11, a second guide member 30 is disposedalong the scroll part 11 d as shown in FIGS. 5, 8, and 9. This guidemember 30 is provided on the bottom side of the top wall 11 a of thehousing 11, and a guiding-direction rear edge 31 is made to face thepassage opening 23. As a result, the cross-sectional shape of thehousing 11 passing through the axis SC is substantially uniform betweenthe portion having the scroll part 11d and the portion not having thescroll part 11 d. Therefore, in mulching mode, the cut grass can besufficiently moved in a revolving motion in the revolving direction Rcwithin the housing 11. Work in mulching mode can be efficientlyperformed.

A shutter mechanism 40 is provided on the internal peripheral surface ofthe housing 11 (the internal peripheral surface of the external cylinder11 b) as shown in FIG. 3. The shutter mechanism 40 is composed of arotating disc 41 rotatably attached to the top wall 11 a inside thehousing 11, a shutter body 42 attached to the outside edge of therotating disc 41, an arm 43 attached at the proximal end to the rotatingdisc 41, an operating lever 44 connected to the distal end of the arm43, and an operation guider 45 provided in the top surface of the rearpart of the housing 11. The rotating disc 41 is an annular horizontalplate positioned on the same axis as the axis SC.

The rotating disc 41 and the shutter body 42 are moveable componentspositioned inside the housing 11. When the rotating disc 41 and theshutter body 42 in the shutter mechanism 40 are hereinafter referred tocollectively, they will be referred to as the “moveable components 41,42” positioned inside the housing 11.

The shutter body 42 is a component obtained by bend-molding a platematerial, and is composed of a horizontal section 42 a extending fromthe outside edge of the rotating disc 41 toward the external cylinder 11b of the housing 11, and a vertical section 42 b curving from the distalend of the horizontal section 42 a and falling along the internalperipheral surface of the external cylinder 11 b, as shown in FIGS. 3,5, and 10. The corner 42 c between the horizontal section 42 a and thevertical section 42 b is formed into a comparatively wide arc shapematching the outside corner 11 e of the scroll part 11 d. The entireshape of the shutter body 42 is substantially a fan shape centeredaround the axis SC when the shutter body 42 is viewed from below. Such ashutter body 42 is capable of rotating together with the rotating disc41 around the axis SC.

The operating lever 44 is attached to the arm 43 such that the lever canswing vertically and the horizontal swinging of the lever is restricted,as shown in FIG. 3. Furthermore, the operating lever 44 is urged towarda neutral position shown by the solid lines by a return spring 46. Theoperation guider 45 has a horizontally long guiding oblong hole 45 athrough which the operating lever 44 passes, and a plurality (e.g. five)of positioning grooves 45 b provided along the guiding oblong hole 45 a,as shown in FIGS. 2 and 3. The operation of the operating lever 44 canbe guided by the operation guider 45. The position of the positioninggroove 45 b at one end of the guiding oblong hole 45 a designates thefully closed position, and the position of the positioning groove 45 bat the other end of the guiding oblong hole 45 a designates the fullyopen position. The intervals of the positioning grooves 45 b arepreferably set so that the open position of the shutter body 42 changesin 25% intervals, for example.

As is made clear from the above description, the shutter mechanism 40has a shutter body 42 provided in the passage opening 23 which facesinto the housing 11 in the cut grass conveyor passage 21. The shutterbody 42 is capable of pivoting about the axis SC of the output shaft 15a as a pivotal center. The passage opening 23 can be opened and closedand the open position can be adjusted by the shutter body 42. Theshutter body 42 can be pivotably operated by the operating lever 44.

FIG. 8 shows that the cut grass conveyor passage 21 extends rearward andupward from the housing 11; and also that in the scroll part 11 d, theguide member 30 is provided at a fixed distance below the top wall 11 a,and the height of the guiding-direction rear edge 31 of the guide member30 is set to a higher position than the bottom end of the passageopening 23. The guiding-direction rear edge 31 faces toward the passageopening 23.

FIG. 9 shows an expanded view of the relationship between the housing11, the cutting blade 14, the passage opening 23 of the cut grassconveyor passage 21, the guide member 30, and the shutter body 42. Theheight of the guide member 30 in the scroll part 11 d is substantiallythe same as the height of the shutter body 42. Therefore, although thecut grass conveyor passage 21 is provided to the housing 11 and theshutter body 42 is provided to the scroll part 11 d, changes in thecross section of the scroll part 11 d (changes in the cross-sectionalshape or size) are comparatively small. As a result, the air and cutgrass can be made to move smoothly and sufficiently in a revolvingmotion through the scroll part 11 d.

In the shutter body 42, a superposed section 42 e folded up into thearea above the guide member 30 is integrally formed on anopening/closing distal end 42 d facing the guiding-direction rear edge31 of the guide member 30, as shown in FIGS. 5, 8, and 9. Therefore,when the shutter body 42 is fully closed, part of the superposed section42 e is vertically superposed over the guiding-direction rear edge 31.The distal end 32 of the guide member 30 is inclined so that the end isin contact with the bottom surface of the top wall 11 a.

The shutter mechanism 40 has a kicker 47 on the moveable components 41,42 positioned inside the housing 11, as shown in FIGS. 3, 5, and 10.This kicker 47 is a member for regulating the revolving flow of cutgrass inside the housing 11 and guiding the cut grass to the bottom ofthe housing 11 in mulching mode. In other words, the kicker 47 guidesthe cut grass revolving in the revolving direction Rc about the outputshaft 15 a to the interior of the housing 11 (the external peripheralsurface of the internal cylinder 11 c) as indicated by the arrow W2, andalso to the bottom of the housing 11. The kicker 47 fulfilling this typeof role is positioned inside the housing 11 in a section of the housing11 near the external periphery, i.e., on the internal peripheral sectionof the external cylinder 11 b or in proximity thereto (morespecifically, positioned in the outside corner 11 e or in proximitythereto).

To be more specific, the kicker 47 is provided to the shutter body 42and is positioned in the corner 42 c between the horizontal section 42 aand the vertical section 42 b or in proximity to the corner, as shown inFIG. 10. For example, the entire kicker 47 is firmly bonded to theshutter body 42, and is attached to the horizontal section 42 a by ascrew 48, or by welding, caulking, or other various attachmentconfigurations. When the shutter mechanism 40 (FIG. 5) is switched tobagging mode, the kicker 47 and the shutter body 42 together becomepositioned away from the cut grass conveyor passage 21 (FIG. 5). Thistype of kicker 47 is formed so as to have a substantially triangularshape in both a plan view (underside view as well) and a side view, soas to taper in the direction opposing the revolving direction Rc inwhich the cut grass revolves, i.e., in the opposite direction of therevolving direction Rc.

When the housing 11 (FIG. 3) is viewed from the bottom side, the kicker47 has the following configuration.

A tapering distal end 47 a in the kicker 47 is positioned in the corner42 c between the horizontal section 42 a and the vertical section 42 b.One side 47 b in the triangular kicker 47 is connected along theexternal side of the vertical section 42 b. This side 47 b is inclinedso that the part in the tapering distal end 47 a is nearest to thehorizontal section 42 a, and as the side moves in the revolvingdirection Rc it becomes progressively farther away from the horizontalsection 42 a. The part in the side 47 b at the rear end 47 c is farthestfrom the horizontal section 42 a.

When the housing 11 (FIG. 3) and the kicker 47 are viewed from thebottom side, the three apexes of the triangular kicker 47 are defined asfollows. The tapering distal end 47 a is referred to as the “first apex47 a.” The rear end 47 c is referred to as the “second apex 47 c.” Theremaining end 47 d is referred to as the “third apex 47 d.” The thirdapex 47 d is separated farthest from the horizontal section 42 a,similar to the second apex 47 c.

Thus, the kicker 47 has a substantially triangular shape in a plan view,which tapers in a direction opposing the revolving direction Rc in whichthe cut grass flows. The revolving current flow is efficiently dispersedin the radial direction of the housing 11 (the direction of the internalcylinder 11 c shown in FIG. 5) by the substantially triangular kicker47. Therefore, cut grass revolving at a high speed can be efficientlyguided in the radial direction of the housing 11 shown in FIG. 5.

Next, the overall action of the lawnmower 10 having the above-describedconfiguration will be described. FIGS. 11 and 12 correspond to FIG. 9.FIGS. 13 through 15 correspond to FIG. 5.

FIGS. 9 and 13 show that the shutter body 42 is operated to the fullyclosed position (open position 0%) by setting the operating lever 44 tothe fully closed position. The passage opening 23 is closed by theshutter body 42, whereby the lawnmower 10 is set to the formation usedin mulching mode, the grass cut by the cutting blade 14 (the cut grass)can be cut even finer within the housing 11, and the grass can bedischarged out below the housing 11.

FIGS. 11 and 14 show that the shutter body 42 has been operated to ahalf-open position (open position 50%) by setting the operating lever 44to the half-open position. By opening the passage opening 23 to thedesired open position by the shutter body 42, the lawnmower 10 can beset to the formation used in intermediate mode (the intermediate modebetween the bagging mode and the mulching mode), and some of the cutgrass can be returned to the ground surface while the rest can be storedin the cut grass storage container 22 (see FIG. 1).

FIGS. 12 and 15 show that the shutter body 42 has been operated to thefully open position (open position 100%) by setting the operating lever44 to the fully open position. By fully opening the passage opening 23,the lawnmower 10 can be set to the formation used in the bagging mode,and the cut grass can be stored in the cut grass storage container 22(FIG. 1).

Thus, the lawnmower can be suitably switched between: (1) a bagging modein which the shutter body 42 is fully open and the cut grass is storedin the cut grass storage container 22, (2) a mulching mode in which theshutter body 42 is fully closed and the cut grass is discharged outbelow the housing 11, and (3) an intermediate mode between the baggingmode and the mulching mode in which the shutter body 42 is set to adesired open position.

Furthermore, by operating the shutter body 42 to a desired openposition, the manner in which cut grass is discharged can be preciselyset as desired according to the state of the lawn Gr (FIG. 1), thefinished mowed conditions, and the user's preferences. Furthermore, theamount of discharged flowing cut grass which is discharged from thehousing 11 to the cut grass storage container 22 can be reduced byswitching to the intermediate mode. As a result, the cut grass remainsin the cut grass storage container 22 for a longer amount of time, andthe frequency with which the cut grass storage container 22 is replacedcan therefore be reduced.

Next, the action of the lawnmower 10 with a guide member 25 provided tothe housing 11 will be described.

In the bagging mode shown in FIG. 15, the cutting blade 14 rotatesaround the shaft 15 a (the output shaft 15 a) and cuts grass, and arevolving flow centered around the output shaft 15 a is created insidethe housing 11. The grass that has been cut (the cut grass) is made torevolve around the output shaft 15 a inside the housing 11 by therevolving flow, and is delivered to the cut grass conveyor passage 21.

The farther from the axis SC, the faster the revolving speed when thecut grass is moved in a revolving motion within the housing 11 by therotation of the cutting blade 14. In other words, the speed of therevolving flow in the external periphery of the housing 11 is fasterthan the speed of the revolving flow in the vicinity of the output shaft15 a. Specifically, the speed of the flow revolving through the passage11 d (scroll part 11 d) having a substantially annular shape in a planview is the slowest in the vicinity of the internal cylinder 11 c. Theguide member 25 is disposed in the inside corner 11 f (see FIG. 7) wherethe speed is low or in the vicinity of the corner. The guide member 25guides the cut grass revolving at a low speed around the output shaft 15a into the cut grass conveyor passage 21 while guiding the cut grass tothe external periphery of the housing 11 (toward the external cylinder11 b) where the revolving speed is fast.

Therefore, since the revolving cut grass flows smoothly, the cut grasscan be efficiently prevented from stopping around the output shaft 15 a(known as grass buildup). Since the problem of grass buildup can beresolved, the lawnmower 10 can be cleaned and inspected less frequently.Moreover, the revolving speed of substantially all of the cut grass is ahigh speed. Substantially all of the cut grass can be quickly deliveredfrom the housing 11 to the cut grass conveyor passage 21 and efficientlystored in the cut grass storage container 22 (FIG. 1). As a result, thestorage performance with which the cut grass is stored in the cut grassstorage container 22 can be improved. Moreover, a simple configurationin which merely the guide member 25 is provided inside the housing 11 issufficient.

The following is a description of the action of a lawnmower 10 having ashutter mechanism 40 and a kicker 47 in addition to the guide member 25in the housing 11.

The kicker 47 is positioned either in the external peripheral area ofthe housing 11 or in proximity thereto, and the kicker guides the flowof the cut grass downward while adjusting the flow of the cut grass,which revolves within the housing 11. The cut grass is discharged outbelow the housing 11 by switching the shutter mechanism 40 to themulching mode shown in FIG. 13. Furthermore, the flow of cut grassrevolving within the housing 11 is led to the bottom of the housing 11by the kicker 47. Therefore, when the lawnmower 10 is used in themulching mode, the cut grass can be efficiently discharged out below thehousing 11. During the mulching mode, the guide member 25 guides the cutgrass revolving at a low speed around the output shaft 15 a within thehousing 11 to the external periphery of the housing 11.

Thus, since both the guide member 25 and the kicker 47 are disposedinside the housing 11, the flow of the cut grass revolving within thehousing 11 can be distributed so as to be uniform during the mulchingmode. Moreover, the problem of grass buildup can be prevented by theguide member 25. Therefore, the cut grass can be efficiently dischargedout below the housing 11. The shutter body 42 closes off the cut grassconveyor passage 21 in the mulching mode. At this time, the kicker 47and the shutter body 42 together are in a position of closing off thecut grass conveyor passage 21, which is not actually necessary becausethe lawnmower is not in the bagging mode.

Alternatively, switching the shutter mechanism 40 to the bagging modeshown in FIG. 15 causes the shutter mechanism 40 to move so as todeliver cut grass from the housing 11 to the cut grass storage container22. At this time, the kicker 47 moves together with the moveablecomponents 41, 42 of the shutter mechanism 40.

In other words, when the shutter body 42 has moved away from theposition of the cut grass conveyor passage 21 (the cut grass conveyorpassage 21 has been opened), the kicker 47 moves together with theshutter body 42 to a position of not affecting “the flow of cut grassfrom the housing 11 into the cut grass conveyor passage 21.” Therefore,in the bagging mode, the “flow of cut grass from the housing 11 into thecut grass storage container 22” is not hindered by the kicker 47.Consequently, when the lawnmower 10 is used in the bagging mode, the cutgrass can be efficiently stored in the cut grass storage container 22(FIG. 1).

Furthermore, since the kicker 47 is provided to the small-sized moveablecomponents 41, 42 in the shutter mechanism 40, it is easier to providethe kicker 47 than when the kicker 47 is provided to a large-sizedcomponent such as the housing 11, and fewer steps are needed to providethe kicker. Moreover, a large-sized component such as the housing 11does not need to be machined in any manner.

In the present invention, the drive source is not limited to the engine15, and the drive source may also be an electric motor, for example.

The cut grass storage container 22 is not limited to a grass bag, andmay also be a box, for example.

The shutter body 42 is preferably configured so as to be capable ofadjusting the open position of the passage opening 23, and the shutterbody 42 may have any shape, dimensions, and constituent material.

The guide member 25 and the kicker 47 may have any dimensions andconstituent materials.

The lawnmower 10 of the present invention is suitable for use as arotary lawnmower which can be used in both a bagging mode and a mulchingmode.

Obviously, various minor changes and modifications of the presentinvention are possible in light of the above teaching. It is thereforeto be understood that within the scope of the appended claims theinvention may be practiced otherwise than as specifically described.

1. A lawnmower comprising: a cutting blade capable of rotating about ashaft extending substantially perpendicular to a lawn; a downwardly-openhousing for housing the cutting blade, the housing having a scroll part;and a cut grass conveyor passage extending rearwardly from the housingand designed to allow attachment of a cut grass storage containerthereto, the grass cut by the cutting blade being delivered to the cutgrass conveyor passage while revolving about a shaft within the housing,wherein the housing has a movable shutter mechanism, a first non-movableguide member and a second non-movable guide member provided therein,when the first guide member is viewed from a housing bottom side, thefirst guide member has an outer surface which tapers downwardly towardthe housing bottom side in a direction opposite a direction in which thegrass revolves for guiding the grass revolving about the shaft toward anouter periphery of the housing while also guiding the grass to the cutgrass conveyor passage, the first guide member being positioned upstreamof the second guide member in the direction in which the grass revolves.2. The lawnmower of claim 1, wherein the housing comprises asubstantially horizontal top wall, an external cylinder and an internalcylinder disposed around the shaft and extending downward from the topwall, and an annular space defined by the top wall, the externalcylinder and the internal cylinder, the annular space defining thehousing scroll part and is formed so that cut grass is directed to thecut grass conveyor passage while revolving, and the first guide memberis disposed in the space at a corner between the top wall and theinternal cylinder or in proximity to the corner.
 3. The lawnmower ofclaim 2, wherein the first guide member is formed into a triangularshape having a tapering distal end disposed in the corner, a sideextending along an external side of the internal cylinder to a rear end,the side being inclined so that the distal end is nearest to the housingtop wall and the rear end is spaced from the housing top wall, and aremaining end disposed away from the external side of the internalcylinder.
 4. The lawnmower of claim 1, wherein the shutter mechanism iscapable of being switched between a bagging mode in which the cut grassconveyor passage is opened so that the grass is delivered from thehousing to the cut grass storage container, and a mulching mode in whichthe cut grass conveyor passage is closed so that the grass is dischargedout below the housing, and a kicker is provided on the shutter mechanismand is movable therewith for regulating the revolving flow of the grasswithin the housing and guiding the grass to a bottom of the housingduring the mulching mode, and is disposed inside the housing in asection close to the external periphery of the housing or in proximityto the section.
 5. The lawnmower of claim 3, wherein both the distal endand the remaining end are adjacent the housing top wall.
 6. Thelawnmower of claim 4, wherein the shutter mechanism includes shutterbody configured to at least partially rotate about an axis of the shaft,the shutter body selectively opening and closing an opening of theconveyor passage, the shutter body having a horizontal section extendingtoward an external cylinder of the housing and a vertical sectionextending from a distal end of the horizontal section, a corner betweenthe horizontal section and the vertical section mirroring an outsidecorner of the housing scroll part.
 7. The lawnmower of claim 6, whereinthe kicker is positioned in proximity to the corner of the shuttermechanism and is formed into a triangular shape which tapers in adirection opposite a direction in which the grass revolves.
 8. Thelawnmower of claim 7, wherein the kicker has a tapering distal endpositioned in the corner, a side extending along an external side of thevertical section to a rear end, the side being inclined so that thedistal end is nearest to the horizontal section and the rear end isspaced from the horizontal section, and a remaining end disposed awayfrom the vertical section and spaced from the horizontal section.
 9. Thelawnmower of claim 1, wherein the second guide member is positionedcloser to the conveyor passage than the first guide member and has aguiding-direction rear edge facing an opening of the conveyor passage.10. The lawnmower of claim 9, wherein the second guide member isprovided on a bottom side of the housing and shaped such that across-sectional shape of the housing passing through an axis of theshaft is substantially uniform between a portion of the housing havingthe scroll part and a portion of the housing not having the scroll part.11. A lawnmower comprising: a cutting blade capable of rotating about ashaft extending substantially perpendicular to a lawn; a downwardly-openhousing for housing the cutting blade, the housing having asubstantially horizontal top wall, an external cylinder and an internalcylinder disposed around the shaft and extending downward from the topwall, and an annular space defined by the top wall, the externalcylinder and the internal cylinder; and a cut grass conveyor passageextending rearwardly from the housing and designed to allow attachmentof a cut grass storage container thereto, the grass cut by the cuttingblade being delivered to the cut grass conveyor passage while revolvingabout a shaft within the housing, wherein the housing has a first guidemember disposed in the space at a corner between the top wall and theinternal cylinder or in proximity to the corner, the first guide memberbeing formed into a triangular shape having a tapering distal enddisposed in the corner, a side extending along an external side of theinternal cylinder to a rear end, the side being inclined in a directionopposite a direction in which the grass revolves so that the distal endis nearest to the housing top wall and the rear end is spaced from thehousing top wall, and a remaining end disposed away from the externalside of the internal cylinder, the first guide member guiding the grassrevolving about the shaft toward an outer periphery of the housing whilealso guiding the grass to the cut grass conveyor passage; and whereinthe housing has a kicker for regulating the revolving flow of the grasswithin the housing, the kicker being disposed in a portion of theannular space which is diametrically opposed to that portion of theannular space having the first guide member.
 12. The lawnmower of claim11, wherein the remaining end of the first guide member is in contactwith the housing top wall.
 13. The lawnmower of claim 11, furthercomprising: a shutter mechanism provided in the housing and capable ofbeing switched between a bagging mode in which the cut grass conveyorpassage is opened so that the grass is delivered from the housing to thecut grass storage container, and a mulching mode in which the cut grassconveyor passage is closed so that the grass is discharged out below thehousing; the kicker provided on the shutter mechanism and being formedinto a triangular shape which tapers in a direction opposite a directionin which the grass revolves for guiding the grass to a bottom of thehousing during the mulching mode; and a second guide member provided inthe housing, the second guide member being separate from the shuttermechanism and positioned between the first guide member and the shuttermechanism, the second guide member having a rear edge facing an openingof the conveyor passage.